cvs commit: src/sys/i386/i386 pmap.c src/sys/kern subr_witness.c

John Baldwin jhb at FreeBSD.org
Mon Aug 9 11:44:34 PDT 2004


On Sunday 08 August 2004 12:27 am, Kris Kennaway wrote:
> On Wed, Aug 04, 2004 at 04:34:03PM -0400, John Baldwin wrote:
> > On Wednesday 04 August 2004 04:31 pm, John Baldwin wrote:
> > > jhb         2004-08-04 20:31:19 UTC
> > >
> > >   FreeBSD src repository
> > >
> > >   Modified files:
> > >     sys/i386/i386        pmap.c
> > >     sys/kern             subr_witness.c
> > >   Log:
> > >   Remove a potential deadlock on i386 SMP by changing the lazypmap ipi
> > > and spin-wait code to use the same spin mutex (smp_tlb_mtx) as the TLB
> > > ipi and spin-wait code snippets so that you can't get into the
> > > situation of one CPU doing a TLB shootdown to another CPU that is doing
> > > a lazy pmap shootdown each of which are waiting on each other.  With
> > > this change, only one of the CPUs would do an IPI and spin-wait at a
> > > time.
> >
> > Both this patch and the previous I have tested locally and also sent out
> > to current@ for testing.  However, I received zero feedback (not even
> > useless feedback), so they may theoretically be risky.
>
> Isn't this the patch I tested for you and reported that it did not fix
> the problem?

Yes, but I sent out _two_ patches to current@ and you didn't test the second 
one I guess.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org


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